I want to create a video sequence in Sprite Kit and use the following code:
#interface VideScreenNode()
#end
#implementation VideScreenNode
- (void)setupVideoSequence
{
AVPlayerItem * intro = [AVPlayerItem playerItemWithURL:[self geturlFromFileName:#"Video1" andType:#"mp4"]];
AVPlayerItem * video1 = [AVPlayerItem playerItemWithURL:[self geturlFromFileName:#"Video2" andType:#"mp4"]];
AVPlayerItem * video2 = [AVPlayerItem playerItemWithURL:[self geturlFromFileName:#"Video3" andType:#"mp4"]];
AVPlayerItem * video3 = [AVPlayerItem playerItemWithURL:[self geturlFromFileName:#"Video4" andType:#"mp4"]];
AVPlayerItem * video4 = [AVPlayerItem playerItemWithURL:[self geturlFromFileName:#"Video5" andType:#"mp4"]];
AVPlayerItem * outro = [AVPlayerItem playerItemWithURL:[self geturlFromFileName:#"Video6" andType:#"mp4"]];
AVQueuePlayer * queuePlayer = [[AVQueuePlayer alloc] initWithItems:#[intro, video1, video2, video3, video4, outro]];
SKVideoNode * sequenceNode = [[SKVideoNode alloc] initWithAVPlayer: queuePlayer];
sequenceNode.position = CGPointMake(512, 384);
[sequenceNode play];
[self addChild:sequenceNode];
}
#pragma mark - helper
- (NSURL *)geturlFromFileName:(NSString *)name
andType:(NSString *)type
{
return [NSURL fileURLWithPath: [[NSBundle mainBundle] pathForResource: name ofType:type]];
}
The video sequence works just fine, but there is a small interruption between each clip. How do I achieve a seamless transition?
Thanks in advance.
You want to add in a call on the AVQueuePlayer that you have. Such as:
[queuePlayer prerollAtRate:float completionHandler:^(BOOL finished)completionHandler];
This will load the files into memory and prepare them to play. This will have an impact on performance, depending on the size of the clips. It should smooth out the transitions that you have. However, you will need to watch out, as if the status property is not AVPlayerStatusReadyToPlay, this will fail.
Related
I've been trying to play music in my SpriteKit game and used the AVAudioPlayerNode class to do so via AVAudioPCMBuffers. Every time I exported my OS X project, it would crash and give me an error regarding audio playback. After banging my head against the wall for the last 24 hours I decided to re-watch WWDC session 501 (see 54:17). My solution to this problem was what the presenter used, which is to break the frames of the buffer into smaller pieces to break up the audio file being read.
NSError *error = nil;
NSURL *someFileURL = ...
AVAudioFile *audioFile = [[AVAudioFile alloc] initForReading: someFileURL commonFormat: AVAudioPCMFormatFloat32 interleaved: NO error:&error];
const AVAudioFrameCount kBufferFrameCapacity = 128 * 1024L;
AVAudioFramePosition fileLength = audioFile.length;
AVAudioPCMBuffer *readBuffer = [[AvAudioPCMBuffer alloc] initWithPCMFormat: audioFile.processingFormat frameCapacity: kBufferFrameCapacity];
while (audioFile.framePosition < fileLength) {
AVAudioFramePosition readPosition = audioFile.framePosition;
if (![audioFile readIntoBuffer: readBuffer error: &error])
return NO;
if (readBuffer.frameLength == 0) //end of file reached
break;
}
My current problem is that the player only plays the last frame read into the buffer. The music that I'm playing is only 2 minutes long. Apparently, this is too long to just read into the buffer outright. Is the buffer being overwritten every time the readIntoBuffer: method is called inside the loop? I'm such a noob at this stuff...how can I get the entire file played?
If I can't get this to work, what is a good way to play music (2 different files) across multiple SKScenes?
This is the solution that I came up with. It's still not perfect, but hopefully it will help someone who is in the same predicament that I've found myself in. I created a singleton class to handle this job. One improvement that can be made in the future is to only load sound effects and music files needed for a particular SKScene at the time they are needed. I had so many issues with this code that I don't want to mess with it now. Currently, I don't have too many sounds, so it's not using an excessive amount of memory.
Overview
My strategy was the following:
Store the audio file names for the game in a plist
Read from that plist and create two dictionaries (one for music and one for short sound effects)
The sound effect dictionary is composed of a AVAudioPCMBuffer and a AVAudioPlayerNode for each of the sounds
The music dictionary is compose of an array of AVAudioPCMBuffers, an array of timestamps for when those buffers should be played in queue, a AVAudioPlayerNode and the sample rate of the original audio file
The sample rate is necessary for figuring out the time at which each buffer should be played (you'll see the calculations done in code)
Create an AVAudioEngine and get the main mixer from the engine and attach all AVAudioPlayerNodes to the mixer (as per usual)
Play sound effects or music using their various methods
sound effect playing is straightforward...call method -(void) playSfxFile:(NSString*)file;
and it plays a sound
for music, I just couldn't find a good solution without invoking the help of the scene trying to play the music. The scene will call -(void) playMusicFile:(NSString*)file;and it will schedule the buffers to play in order that they were created. I couldn't find a good way to get the music to repeat once completed within my AudioEngine class so I decided to get the scene to check in its update: method whether or not the music was playing for a particular file and if not, play it again (not a very slick solution, but it works)
AudioEngine.h
#import <Foundation/Foundation.h>
#interface AudioEngine : NSObject
+(instancetype)sharedData;
-(void) playSfxFile:(NSString*)file;
-(void) playMusicFile:(NSString*)file;
-(void) pauseMusic:(NSString*)file;
-(void) unpauseMusic:(NSString*)file;
-(void) stopMusicFile:(NSString*)file;
-(void) setVolumePercentages;
-(bool) isPlayingMusic:(NSString*)file;
#end
AudioEngine.m
#import "AudioEngine.h"
#import <AVFoundation/AVFoundation.h>
#import "GameData.h" //this is a class that I use to store game data (in this case it is being used to get the user preference for volume amount)
#interface AudioEngine()
#property AVAudioEngine *engine;
#property AVAudioMixerNode *mixer;
#property NSMutableDictionary *musicDict;
#property NSMutableDictionary *sfxDict;
#property NSString *audioInfoPList;
#property float musicVolumePercent;
#property float sfxVolumePercent;
#property float fadeVolume;
#property float timerCount;
#end
#implementation AudioEngine
int const FADE_ITERATIONS = 10;
static NSString * const MUSIC_PLAYER = #"player";
static NSString * const MUSIC_BUFFERS = #"buffers";
static NSString * const MUSIC_FRAME_POSITIONS = #"framePositions";
static NSString * const MUSIC_SAMPLE_RATE = #"sampleRate";
static NSString * const SFX_BUFFER = #"buffer";
static NSString * const SFX_PLAYER = #"player";
+(instancetype) sharedData {
static AudioEngine *sharedInstance = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedInstance = [[self alloc] init];
[sharedInstance startEngine];
});
return sharedInstance;
}
-(instancetype) init {
if (self = [super init]) {
_engine = [[AVAudioEngine alloc] init];
_mixer = [_engine mainMixerNode];
_audioInfoPList = [[NSBundle mainBundle] pathForResource:#"AudioInfo" ofType:#"plist"]; //open a plist called AudioInfo.plist
[self setVolumePercentages]; //this is created to set the user's preference in terms of how loud sound fx and music should be played
[self initMusic];
[self initSfx];
}
return self;
}
//opens all music files, creates multiple buffers depending on the length of the file and a player
-(void) initMusic {
_musicDict = [NSMutableDictionary dictionary];
_audioInfoPList = [[NSBundle mainBundle] pathForResource: #"AudioInfo" ofType: #"plist"];
NSDictionary *audioInfoData = [NSDictionary dictionaryWithContentsOfFile:_audioInfoPList];
for (NSString *musicFileName in audioInfoData[#"music"]) {
[self loadMusicIntoBuffer:musicFileName];
AVAudioPlayerNode *player = [[AVAudioPlayerNode alloc] init];
[_engine attachNode:player];
AVAudioPCMBuffer *buffer = [[_musicDict[musicFileName] objectForKey:MUSIC_BUFFERS] objectAtIndex:0];
[_engine connect:player to:_mixer format:buffer.format];
[_musicDict[musicFileName] setObject:player forKey:#"player"];
}
}
//opens a music file and creates an array of buffers
-(void) loadMusicIntoBuffer:(NSString *)filename
{
NSURL *audioFileURL = [[NSBundle mainBundle] URLForResource:filename withExtension:#"aif"];
//NSURL *audioFileURL = [NSURL URLWithString:[[NSBundle mainBundle] pathForResource:filename ofType:#"aif"]];
NSAssert(audioFileURL, #"Error creating URL to audio file");
NSError *error = nil;
AVAudioFile *audioFile = [[AVAudioFile alloc] initForReading:audioFileURL commonFormat:AVAudioPCMFormatFloat32 interleaved:NO error:&error];
NSAssert(audioFile != nil, #"Error creating audioFile, %#", error.localizedDescription);
AVAudioFramePosition fileLength = audioFile.length; //frame length of the audio file
float sampleRate = audioFile.fileFormat.sampleRate; //sample rate (in Hz) of the audio file
[_musicDict setObject:[NSMutableDictionary dictionary] forKey:filename];
[_musicDict[filename] setObject:[NSNumber numberWithDouble:sampleRate] forKey:MUSIC_SAMPLE_RATE];
NSMutableArray *buffers = [NSMutableArray array];
NSMutableArray *framePositions = [NSMutableArray array];
const AVAudioFrameCount kBufferFrameCapacity = 1024 * 1024L; //the size of my buffer...can be made bigger or smaller 512 * 1024L would be half the size
while (audioFile.framePosition < fileLength) { //each iteration reads in kBufferFrameCapacity frames of the audio file and stores it in a buffer
[framePositions addObject:[NSNumber numberWithLongLong:audioFile.framePosition]];
AVAudioPCMBuffer *readBuffer = [[AVAudioPCMBuffer alloc] initWithPCMFormat:audioFile.processingFormat frameCapacity:kBufferFrameCapacity];
if (![audioFile readIntoBuffer:readBuffer error:&error]) {
NSLog(#"failed to read audio file: %#", error);
return;
}
if (readBuffer.frameLength == 0) { //if we've come to the end of the file, end the loop
break;
}
[buffers addObject:readBuffer];
}
[_musicDict[filename] setObject:buffers forKey:MUSIC_BUFFERS];
[_musicDict[filename] setObject:framePositions forKey:MUSIC_FRAME_POSITIONS];
}
-(void) initSfx {
_sfxDict = [NSMutableDictionary dictionary];
NSDictionary *audioInfoData = [NSDictionary dictionaryWithContentsOfFile:_audioInfoPList];
for (NSString *sfxFileName in audioInfoData[#"sfx"]) {
AVAudioPlayerNode *player = [[AVAudioPlayerNode alloc] init];
[_engine attachNode:player];
[self loadSoundIntoBuffer:sfxFileName];
AVAudioPCMBuffer *buffer = [_sfxDict[sfxFileName] objectForKey:SFX_BUFFER];
[_engine connect:player to:_mixer format:buffer.format];
[_sfxDict[sfxFileName] setObject:player forKey:SFX_PLAYER];
}
}
//WARNING: make sure that the sound fx file is small (roughly under 30 sec) otherwise the archived version of the app will crash because the buffer ran out of space
-(void) loadSoundIntoBuffer:(NSString *)filename
{
NSURL *audioFileURL = [NSURL URLWithString:[[NSBundle mainBundle] pathForResource:filename ofType:#"mp3"]];
NSAssert(audioFileURL, #"Error creating URL to audio file");
NSError *error = nil;
AVAudioFile *audioFile = [[AVAudioFile alloc] initForReading:audioFileURL commonFormat:AVAudioPCMFormatFloat32 interleaved:NO error:&error];
NSAssert(audioFile != nil, #"Error creating audioFile, %#", error.localizedDescription);
AVAudioPCMBuffer *readBuffer = [[AVAudioPCMBuffer alloc] initWithPCMFormat:audioFile.processingFormat frameCapacity:(AVAudioFrameCount)audioFile.length];
[audioFile readIntoBuffer:readBuffer error:&error];
[_sfxDict setObject:[NSMutableDictionary dictionary] forKey:filename];
[_sfxDict[filename] setObject:readBuffer forKey:SFX_BUFFER];
}
-(void)startEngine {
[_engine startAndReturnError:nil];
}
-(void) playSfxFile:(NSString*)file {
AVAudioPlayerNode *player = [_sfxDict[file] objectForKey:#"player"];
AVAudioPCMBuffer *buffer = [_sfxDict[file] objectForKey:SFX_BUFFER];
[player scheduleBuffer:buffer atTime:nil options:AVAudioPlayerNodeBufferInterrupts completionHandler:nil];
[player setVolume:1.0];
[player setVolume:_sfxVolumePercent];
[player play];
}
-(void) playMusicFile:(NSString*)file {
AVAudioPlayerNode *player = [_musicDict[file] objectForKey:MUSIC_PLAYER];
if ([player isPlaying] == NO) {
NSArray *buffers = [_musicDict[file] objectForKey:MUSIC_BUFFERS];
double sampleRate = [[_musicDict[file] objectForKey:MUSIC_SAMPLE_RATE] doubleValue];
for (int i = 0; i < [buffers count]; i++) {
long long framePosition = [[[_musicDict[file] objectForKey:MUSIC_FRAME_POSITIONS] objectAtIndex:i] longLongValue];
AVAudioTime *time = [AVAudioTime timeWithSampleTime:framePosition atRate:sampleRate];
AVAudioPCMBuffer *buffer = [buffers objectAtIndex:i];
[player scheduleBuffer:buffer atTime:time options:AVAudioPlayerNodeBufferInterrupts completionHandler:^{
if (i == [buffers count] - 1) {
[player stop];
}
}];
[player setVolume:_musicVolumePercent];
[player play];
}
}
}
-(void) stopOtherMusicPlayersNotNamed:(NSString*)file {
if ([file isEqualToString:#"menuscenemusic"]) {
AVAudioPlayerNode *player = [_musicDict[#"levelscenemusic"] objectForKey:MUSIC_PLAYER];
[player stop];
}
else {
AVAudioPlayerNode *player = [_musicDict[#"menuscenemusic"] objectForKey:MUSIC_PLAYER];
[player stop];
}
}
//stops the player for a particular sound
-(void) stopMusicFile:(NSString*)file {
AVAudioPlayerNode *player = [_musicDict[file] objectForKey:MUSIC_PLAYER];
if ([player isPlaying]) {
_timerCount = FADE_ITERATIONS;
_fadeVolume = _musicVolumePercent;
[self fadeOutMusicForPlayer:player]; //fade out the music
}
}
//helper method for stopMusicFile:
-(void) fadeOutMusicForPlayer:(AVAudioPlayerNode*)player {
[NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:#selector(handleTimer:) userInfo:player repeats:YES];
}
//helper method for stopMusicFile:
-(void) handleTimer:(NSTimer*)timer {
AVAudioPlayerNode *player = (AVAudioPlayerNode*)timer.userInfo;
if (_timerCount > 0) {
_timerCount--;
AVAudioPlayerNode *player = (AVAudioPlayerNode*)timer.userInfo;
_fadeVolume = _musicVolumePercent * (_timerCount / FADE_ITERATIONS);
[player setVolume:_fadeVolume];
}
else {
[player stop];
[player setVolume:_musicVolumePercent];
[timer invalidate];
}
}
-(void) pauseMusic:(NSString*)file {
AVAudioPlayerNode *player = [_musicDict[file] objectForKey:MUSIC_PLAYER];
if ([player isPlaying]) {
[player pause];
}
}
-(void) unpauseMusic:(NSString*)file {
AVAudioPlayerNode *player = [_musicDict[file] objectForKey:MUSIC_PLAYER];
[player play];
}
//sets the volume of the player based on user preferences in GameData class
-(void) setVolumePercentages {
NSString *musicVolumeString = [[GameData sharedGameData].settings objectForKey:#"musicVolume"];
_musicVolumePercent = [[[musicVolumeString componentsSeparatedByCharactersInSet:
[[NSCharacterSet decimalDigitCharacterSet] invertedSet]]
componentsJoinedByString:#""] floatValue] / 100;
NSString *sfxVolumeString = [[GameData sharedGameData].settings objectForKey:#"sfxVolume"];
_sfxVolumePercent = [[[sfxVolumeString componentsSeparatedByCharactersInSet:
[[NSCharacterSet decimalDigitCharacterSet] invertedSet]]
componentsJoinedByString:#""] floatValue] / 100;
//immediately sets music to new volume
for (NSString *file in [_musicDict allKeys]) {
AVAudioPlayerNode *player = [_musicDict[file] objectForKey:MUSIC_PLAYER];
[player setVolume:_musicVolumePercent];
}
}
-(bool) isPlayingMusic:(NSString *)file {
AVAudioPlayerNode *player = [_musicDict[file] objectForKey:MUSIC_PLAYER];
if ([player isPlaying])
return YES;
return NO;
}
#end
The code is suppose to make a sound either yes or yes 3 play when clicked, but I get an error before I begin to debug that says rand cannot be statically allocated, but I can't put a * there because it's an integer. I am getting a conversion error when I do that. I also tried putting a * before sound, and that solved the error issue but when the button is clicked it wont play anything. So what do I do?
#import "ViewController.h"
#import <AVFoundation/AVAudioPlayer.h>
#interface ViewController ()
#end
#implementation
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}//this is where the error breakpoint is that you show me how to make
- (IBAction)Yes {
NSInteger rand = arc4random_uniform(2);
NSString sound = rand == 0 ? #"yes" : #"yes 3";
NSURL *url = [[NSBundle mainBundle] URLForResource:sound withExtension:#"mp3"];
AVAudioPlayer* audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil];
[audioPlayer play];
}
#end
I've seen this many times before, and it has to do with the fact that your audio player variable is being released before it has a chance to play the file.
You need to create a property for the audio player in your header:
#property (nonatomic, strong) AVAudioPlayer *audioPlayer;
Then in your method access that property instead of the local variable:
- (IBAction)YES {
NSInteger rand = arc4random_uniform(2);
NSString *sound = rand == 0 ? #"yes" : #"yes 3";
NSURL *url = [[NSBundle mainBundle] URLForResource:sound withExtension:#"mp3"];
self.audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil];
[self.audioPlayer play];
}
Note that this has absolutely nothing to do with the sound variable you're messing with. You should be using the * to indicate a pointer when creating that variable, as shown above.
How can I change the volume of the AVPlayer Dynamically? I mean, I want to mute the volume every time a button is pressed. the given code seems to change it in compile time only. How to do it during runtime???
AVURLAsset *asset = [AVURLAsset URLAssetWithURL:[self myAssetURL] options:nil];
NSArray *audioTracks = [asset tracksWithMediaType:AVMediaTypeAudio];
NSMutableArray *allAudioParams = [NSMutableArray array];
for (AVAssetTrack *track in audioTracks) {
AVMutableAudioMixInputParameters *audioInputParams =[AVMutableAudioMixInputParameters audioMixInputParameters];
[audioInputParams setVolume:0.0 atTime:kCMTimeZero];
[audioInputParams setTrackID:[track trackID]];
[allAudioParams addObject:audioInputParams];
}
AVMutableAudioMix *audioZeroMix = [AVMutableAudioMix audioMix];
[audioZeroMix setInputParameters:allAudioParams];
AVPlayerItem *playerItem = [AVPlayerItem playerItemWithAsset:asset];
[playerItem setAudioMix:audioZeroMix];
AVPlayer *player = [AVPlayer playerWithPlayerItem:playerItem];
self.mPlayer = player;
[mPlayer play];
You can send playerItem new instances of AVMutableAudioMix during playback to change levels dynamically. Just link your button to an action method that creates a new AVMutableAudioMix instance (like you have done above) with the appropriate values, and use playerItem's setAudioMix: method to set the new mix values. (If you're working across methods, don't forget to save a reference to your playerItem instance to access it later.)
(N.B. setAudioMix: isn't mentioned explicitly in the AVPlayerItem docs because it is a synthesized setter for the audioMix property.)
In my app, I should play firstvideo at once, and then play second video, which will on repeat. So, at first I used MPMoviePlayerController, but there already was a black screen between two videos. So, I read somewhere, that in my case I should use AVFoundation. That's whe I use AVQueuePLayer with two AVPLayerItem, which I create with my NSURL. But issue is, that after first video finished, there is a long pause. Nearly for 0.5 sec, before second vide o starts. How remove it? What way to use? So, I really appreciate any help! I need it very much, as soon as possible. Thanks!
Here all my methods which I use:
- (void) configureAVPlayer {
self.queuePlayer.actionAtItemEnd = AVPlayerActionAtItemEndPause;
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:#selector(playerItemDidReachEnd:)
name:AVPlayerItemDidPlayToEndTimeNotification
object:self.queuePlayer];
self.isFirstVideoFinished = NO;
[self playVideos];
}
- (void) playVideos {
[self setPlayerItemsForQueue];
[self.videoHolder setPlayer:self.queuePlayer];
}
- (void) setPlayerItemsForQueue {
NSURL *fileURL = [[NSBundle mainBundle]
URLForResource:[self getStringForMode:self.currentMode] withExtension:#"mp4"];
NSMutableString *secondFile = [self getStringForMode:self.currentMode];
[secondFile appendString:#"Second"];
NSURL *secondFileUrl = [[NSBundle mainBundle] URLForResource:secondFile withExtension:#"mp4"];
AVAsset *firstAsset = [AVAsset assetWithURL:fileURL];
AVPlayerItem *firstVideoItem = [AVPlayerItem playerItemWithAsset:firstAsset];//[AVPlayerItem playerItemWithURL:fileURL];
AVAsset *secondAsset = [AVAsset assetWithURL:secondFileUrl];
AVPlayerItem *secondVideoItem = [AVPlayerItem playerItemWithAsset:secondAsset];//[AVPlayerItem playerItemWithURL:secondFileUrl];
self.queuePlayer = [AVQueuePlayer queuePlayerWithItems: [NSArray arrayWithObjects:firstVideoItem, secondVideoItem,nil]];
for (AVPlayerItem *playerItem in self.queuePlayer.items) {
[playerItem addObserver: self forKeyPath: #"status" options:0 context:NULL];
}
}
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object
change:(NSDictionary *)change context:(void *)context {
dispatch_async(dispatch_get_main_queue(), ^{
if ([(AVPlayerItem *)object status] == AVPlayerItemStatusReadyToPlay) {
[self.queuePlayer play];
}
});
}
- (void) playerItemDidReachEnd:(NSNotification*) notification {
NSMutableString *secondFile = [self getStringForMode:self.currentMode];
[secondFile appendString:#"Second"];
NSURL *secondFileUrl = [[NSBundle mainBundle] URLForResource:secondFile withExtension:#"mp4"];
AVPlayerItem *playerItem = [[ AVPlayerItem alloc ] initWithURL:secondFileUrl];
if ([self.queuePlayer canInsertItem:playerItem afterItem:[notification object]]) {
[self.queuePlayer insertItem: playerItem afterItem: nil ];
}
}
Yes, multiple AVPlayer objects are your best option.
I solved this problem with a main timer function which monitored the current playback time of firstVideoItem, and when it was 0.01 seconds from the end, I would flip the players on the alpha channel, so secondVideoItem was visible, then play secondVideoItem.
I also used [secondVideoItem seekToTime:CMTimeMakeWithSeconds(1,1)] before issuing the play command to make sure the second video was initialised and ready to play. This helped a lot.
I have a TabBarController with two tabs and I want to play music on both tabs. Right now I have my code on the main appDelegate
NSURL *url = [NSURL fileURLWithPath:[[NSBundle mainBundle]
pathForResource:#"My Song"
ofType:#"m4a"]]; // My Song.m4a
NSError *error;
self.audioPlayer = [[AVAudioPlayer alloc]
initWithContentsOfURL:url
error:&error];
if (error)
{
NSLog(#"Error in audioPlayer: %#",
[error localizedDescription]);
} else {
//audioPlayer.delegate = self;
[audioPlayer prepareToPlay];
}
but I'm getting the error Program received signal: "SIGABRT" on UIApplicationMain
Is there a better way to accomplish what I'm trying to do? If this is how I should do it, where do I start checking for problems?
yes you can use AVAudioPlayer in App Delegate.
What you need to do is:-
In appDelegate.h file do:-
#import <AVFoundation/AVFoundation.h>
#import <AudioToolbox/AudioToolbox.h>
AVAudioPlayer *_backgroundMusicPlayer;
BOOL _backgroundMusicPlaying;
BOOL _backgroundMusicInterrupted;
UInt32 _otherMusicIsPlaying;
Make backgroundMusicPlayer property and sythesize it.
In appDelegate.m file do:-
Add these lines in did FinishLaunching method
NSError *setCategoryError = nil;
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryAmbient error:&setCategoryError];
// Create audio player with background music
NSString *backgroundMusicPath = [[NSBundle mainBundle] pathForResource:#"SplashScreen" ofType:#"wav"];
NSURL *backgroundMusicURL = [NSURL fileURLWithPath:backgroundMusicPath];
NSError *error;
_backgroundMusicPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:backgroundMusicURL error:&error];
[_backgroundMusicPlayer setDelegate:self]; // We need this so we can restart after interruptions
[_backgroundMusicPlayer setNumberOfLoops:-1]; // Negative number means loop forever
Now implement delegate methods
#pragma mark -
#pragma mark AVAudioPlayer delegate methods
- (void) audioPlayerBeginInterruption: (AVAudioPlayer *) player {
_backgroundMusicInterrupted = YES;
_backgroundMusicPlaying = NO;
}
- (void) audioPlayerEndInterruption: (AVAudioPlayer *) player {
if (_backgroundMusicInterrupted) {
[self tryPlayMusic];
_backgroundMusicInterrupted = NO;
}
}
- (void)tryPlayMusic {
// Check to see if iPod music is already playing
UInt32 propertySize = sizeof(_otherMusicIsPlaying);
AudioSessionGetProperty(kAudioSessionProperty_OtherAudioIsPlaying, &propertySize, &_otherMusicIsPlaying);
// Play the music if no other music is playing and we aren't playing already
if (_otherMusicIsPlaying != 1 && !_backgroundMusicPlaying) {
[_backgroundMusicPlayer prepareToPlay];
if (soundsEnabled==YES) {
[_backgroundMusicPlayer play];
_backgroundMusicPlaying = YES;
}
}
}